by Kim Painter, Special for USA TODAY

by Kim Painter, Special for USA TODAY

More than one-quarter of U.S. children with a history of food allergies have outgrown their sensitivities and can tolerate the foods that once made them sick, a new analysis shows.

But black children, kids with multiple allergies and those with histories of severe reactions are less likely than other kids to recover. Kids with allergies to nuts or fish don't fare as well as those with allergies to eggs, milk, soy and wheat. And kids with those easier-to-overcome allergies don't outgrow them as quickly as observed in earlier generations of children, says Ruchi Gupta, associate professor of pediatrics at Northwestern University Feinberg School of Medicine, Chicago.

Doctors used to see children growing out of milk allergies in preschool years. But now "we see kids really holding on to milk allergies," sometimes into teen years, says Gupta, who presented the unpublished data at a meeting of the American College of Allergy, Asthma and Immunology this week in Anaheim, Calif. The reasons for that shift - and the recent increases in child food allergies - are unknown, she says.

Gupta and her colleagues collected data on 40,000 children and teens nationwide to find 4,433 with current or former food allergies. As the researchers have previously reported, about 8% of children in the United States have current food allergies.

The new report says an additional 3% had food allergies in the past but did not have them at the time of the survey. For example, 41% of milk allergies, 40% of egg allergies, 16% of peanut allergies and 13% of shellfish allergies had been outgrown. The rates get higher as kids age. So 55% of kids over age 10 with a history of egg allergy no longer had the problem, Gupta says.

"Most kids develop tolerance by age 10, but tolerance can develop at any age," she says. "There's always hope."

The tolerance rates found in the study are in line with what allergists see in their offices and what other research has shown, says Scott Sicherer, professor of pediatrics at the Jaffe Food Allergy Institute at Mount Sinai School of Medicine, New York.

Many kids outgrow their allergies, "but they are slower at outgrowing them than in the past," he says.

For kids who remain allergic, the standard treatment is avoiding the food that could make them break out in hives, swell up, wheeze, get an upset stomach or suffer a life-threatening anaphylactic reaction.

But doctors are trying new ways to help more children safely tolerate foods. One method is oral immunotherapy, in which children are given very small, repeated doses of peanut, egg or milk in a doctor's office to see if they can build up tolerance over time. The approach is showing some promise but remains experimental and should never be tried at home, Sicherer says.

In another approach, doctors are letting some allergic kids try muffins, waffles, cakes or other baked products that contain milk or eggs - which are less likely to trigger reactions after thorough heating. Several studies have shown many allergic kids can tolerate the foods. And it's possible that those who keep eating the baked foods might overcome their allergies faster, Sicherer says.

In one such experiment, also reported at this week's meeting, 36 children with egg allergies tried cake baked by their families under a strict recipe, served 1 teaspoon at a time under the watchful eyes of doctors standing by with allergy medicines at Children's Hospital of Philadelphia. More than half of the kids were able to safely eat at least one standard piece of cake, says researcher Rushani Saltzman.

Those kids can now safely go to a party and eat a little birthday cake, she says â?? which is a big deal to many of them.

But, she notes, 16 of the kids had reactions in the hospital test, and many of those reactions were severe. So the initial baked food test should never be tried at home, she stresses.